The objective of this research is to contribute to the long-term success of smoking cessation programs by providing the basis for the development of treatments which enhance the maintenance of abstinence from smoking. Our specific aim is to identify the situational determinants of relapse, so that coping skills that address these situations can be formulated. We are collecting data on the situational correlates for relapse following smoking cessation by debriefing ex-smokers who call an ex-smokers' maintenance hotline. Information is recorded regarding the situation in which the relapse occurred -- including the physical and social environment, the caller's thoughts and feelings, and the antecedent events -- and the caller's attempts to cope with it. Callers are also subsequently followed up to determine their ultimate fate. A related project attempts to predict from pretreatment data to the details of subsequent relapse episodes. A pretreatment assessment of smoking history and motivation and relevant and personality factors is obtained, and the subject is then followed for three months. Relapse episodes during this period are debriefed in the manner described. We will be continuing to collect data on relapse through the use of structured interviews. We plan to perform a cluster analysis on these data in order to identify specific situations which tend to produce relapses. For data from the relapse prediction study, we hope to correlate the stimuli associated with the relapse with pretreatment data.